Conventionally, an air physical quantity sensor has a sensor element for outputting the detected signal in accordance with a specified quantity, the sensor element housed in a recess portion of a sensor body, which opens at an opening portion.
In the sensor as an air physical quantity sensor as shown in Japanese Patent application No. 2015-187603 (referred to as patent document 1, hereinafter), the atmosphere sensor has a sensor filter in a sensor case. The moisture permeable film is bonded to the case by a welding method.
The moisture permeable film having the shape of a circle or an oval and the welded part having the shape of a ring make bonded strength between the welded part and the bottom surface of the sensor case uniform. Since a restoring force continually acts to the welded part and the welded part is easily removed, the moisture permeable film is separated from the case. The moisture permeable film having extensibility make the mesh enlarge, and the filter performance is reduced.
The present disclosure is made in view of the above matters, and it is an object of the present disclosure to provide an air physical quantity sensor, a sensor filter of which is prevented to remove and to deform.